A method of data reduction in a partially encrypted volume includes receiving data to be stored on a storage array, decrypting the data using a first encryption key to generate first decrypted data, and decrypting the data using a second encryption key to generate second decrypted data. The method further includes comparing, by a storage array controller, a first compressibility value of the first decrypted data to a second compressibility value of the second decrypted data. The method further includes storing the first decrypted data if the first compressibility value is greater than or equal to the second compressibility value. The method further includes storing the second decrypted data if the second compressibility value is greater than the first compressibility value.